Question

I am using select() statement that handles multiple client connections using Unix C sockets. I would like to disconnect idle clients – if I don’t get any messages from clients after a certain period. I looked at the select()‘s timeout functionality but that’s for the whole select and not individual clients.

How would you terminate the connection for specific clients?

Answer 1

For a server, you typically call select in a loop. At the top of the loop, you build your file descriptor lists from the client connections. At this point, I would calculate the longest you want to wait in your select (smallest time until the next client connection should be timed out). Then call select with that timeout. After the end of the select, you check each of the connections to see if data was received, a new connection was received, or if a timeout has been reached. Process any data, open/close any connections, and then return to the top of your loop.